diff --git a/src/Application.php b/src/Application.php
index dbdd6a4a..a68e0e67 100644
--- a/src/Application.php
+++ b/src/Application.php
@@ -56,7 +56,7 @@ public function addInitRoboFileCommand($roboFile, $roboClass)
             );
             $output->writeln("<comment>  Edit this file to add your commands! </comment>");
         });
-        $this->add($createRoboFile);
+        $this->addCommand($createRoboFile);
     }
 
     /**
@@ -71,6 +71,6 @@ public function addSelfUpdateCommand($repository = null)
             return;
         }
         $selfUpdateCommand = new \SelfUpdate\SelfUpdateCommand($this->getName(), $this->getVersion(), $repository);
-        $this->add($selfUpdateCommand);
+        $this->addCommand($selfUpdateCommand);
     }
 }
diff --git a/src/Robo.php b/src/Robo.php
index 25cb7884..0c4e5267 100644
--- a/src/Robo.php
+++ b/src/Robo.php
@@ -547,7 +547,7 @@ protected static function registerSingle($app, $handler)
         // If the instance is a Symfony Command, register it with
         // the application
         if ($instance instanceof Command) {
-            $app->add($instance);
+            $app->addCommand($instance);
             return $instance;
         }
 
@@ -555,7 +555,7 @@ protected static function registerSingle($app, $handler)
         $commandFactory = $container->get('commandFactory');
         $commandList = $commandFactory->createCommandsFromClass($instance);
         foreach ($commandList as $command) {
-            $app->add($command);
+            $app->addCommand($command);
         }
         return $instance;
     }
diff --git a/src/Runtime/Runner.php b/src/Runtime/Runner.php
index c345ba02..2eea95af 100644
--- a/src/Runtime/Runner.php
+++ b/src/Runtime/Runner.php
@@ -353,7 +353,7 @@ public function registerCommandClass($app, $commandClass)
         $commandFactory = $container->get('commandFactory');
         $commandList = $commandFactory->createCommandsFromClass($roboCommandFileInstance);
         foreach ($commandList as $command) {
-            $app->add($command);
+            $app->addCommand($command);
         }
         return $roboCommandFileInstance;
     }
diff --git a/src/Task/Base/ParallelExec.php b/src/Task/Base/ParallelExec.php
index ea21da5a..b8a228f1 100644
--- a/src/Task/Base/ParallelExec.php
+++ b/src/Task/Base/ParallelExec.php
@@ -84,12 +84,17 @@ public function printed($isPrinted = true)
     }
 
     /**
-     * @param string|\Robo\Contract\CommandInterface $command
+     * @param string|\Robo\Contract\CommandInterface|Process $command
      *
      * @return $this
      */
     public function process($command)
     {
+        if ($command instanceof Process) {
+            $this->processes[] = $command;
+            return $this;
+        }
+
         // TODO: Symfony 4 requires that we supply the working directory.
         $this->processes[] = Process::fromShellCommandline($this->receiveCommand($command), getcwd());
         return $this;
diff --git a/tests/integration/RoboFileTest.php b/tests/integration/RoboFileTest.php
index a2cef8a7..b4f2d37a 100644
--- a/tests/integration/RoboFileTest.php
+++ b/tests/integration/RoboFileTest.php
@@ -35,7 +35,7 @@ public function setUp(): void
         $this->roboCommandFileInstance->setBuilder($builder);
         $commandList = $this->commandFactory->createCommandsFromClass($this->roboCommandFileInstance);
         foreach ($commandList as $command) {
-            $this->app->add($command);
+            $this->app->addCommand($command);
         }
     }
 
diff --git a/tests/unit/ApplicationTest.php b/tests/unit/ApplicationTest.php
index d01082d2..4d6b8a29 100644
--- a/tests/unit/ApplicationTest.php
+++ b/tests/unit/ApplicationTest.php
@@ -39,7 +39,7 @@ protected function _before()
         $this->roboCommandFileInstance->setBuilder($builder);
         $commandList = $this->commandFactory->createCommandsFromClass($this->roboCommandFileInstance);
         foreach ($commandList as $command) {
-            $this->app->add($command);
+            $this->app->addCommand($command);
         }
     }